Unloader for compound compressors.



No. 834,627. PATENTED OCT. 30, 1906.

v F. VAN D. LONGAGRE. UNLOADEB. POR COMPOUND GOMPRESSORS.

APPLICATION FILED NOV. 23,1904.

2 SHEETS-SHEET 1.

myn/mf No. 834,627. PATENTED OCT. 30, 1906. l P. VAN D. LONGAGRE. UNLOADER POR GOMPOUND GOMPRESSORS.

APPLICATION FILED NOV. 23, 1904.

' 2 SHEETS-SHEET 2.

UNITED sTATEs FREDERICK VAN DUZER LONGACRE,

PATENT oEEioE.

or NEW YORK, N. Y., AssieNoE To NEW JERSEY.

UNLOADEH FOR COMPQUND COM'PRESSORS.

Specification of Letters Patent.

Patented oct. 3o, 1906.

Application led November 23,1904. Serial No. 234,912.

To all whom zit/'may concern: l

Be it known that I, FREDERICK VAN DUZER LoNGAcRE, a citizen of the United Sta-tes, and a resident of the borough. of Manhattan, in the city and State of New York, have invented new and useful Improvements in Unloaders for Compound Compressors, of which the following is a speciiication.A

' The object of my present invention' is. to provide certain improvements in the construction, form, and arrangement of the several parts of an unloader for compound compressors.

This invention is intended articularly for use where the pressure back o the dischargevalves of high `and low pressure cylinders may be removed by opening and closing thel spaces back of the said valves to the atmosphere, the'valve for controlling the loading and unloading of the said valves being under the control of an electromagnet.

In the accompanying drawings, Figure 1 represents the unloader invertical-section,

y the parts being in the -positions which they assume when the electromagnet is denergized and the pressure-ports -are in open communication. Fig. 2 isa similar view showing the positions which the parts assume when the electromagnetis energized and the discharge-valve' pressure-ports are closed Jfrom ythe intercool'er and receiver ressure-ports and open to the atmosphere. 1g. 3 1s a diagrammatic view illustrating anl electric system suitable for use in operating the unloader-.electromagnet, `which view includes details of a compound compressor, its

-intercooler, alreceiver, the discharge-valves, the unloader, and the pipe connectlons beare -tted to slide in tubes 5 `and 6 the lower,

ends of which `are`closedv by removable bottoni caps 7 and 8, having screw-threaded eny. gagements with the said tubes. These cafps serve as stops for supporting the cores 3 and 4 when the electromagnet is denergized.

Two valve-boxes 9 and 10 surmount the. bracket 1, 'the valve-box 9 having step ed depending portions 11 .and 12 and the va vebox having similar stepped dependingl portions 13 14. The larger portions 11 and 130i these valve-boxes are seated in the top lof the bracket, and their smaller portions 12 and 14 are inserted within the tubes 5 and 6 and have screw-threaded engagements therewith., The interior of the valve-box 9 is provided with a valve-chamber 15, the upper end ofwhich is closed by a removable top cap 16. This top cap l16 has a pressure-port 17 therethrough, which port is -itted to be connected to the intercooler 43 of a compound air-compressor 44 through a pipe 45. A valve-seat 18 is formed at the mouthvof this port 17.

A pressure-port 19 leads through the valvebox to the valve-chamber 15, which ressure-port 1s fitted to be connected to the ack of the discharge-valve 46 in the low-pressure cylinder ofthe compound air-compressor 44 through a pipe 47.

A ring 20 is seated in the bottom of l the valve-chamber 15, the bore of the said ring forming an exhaust-port 21, leading to a central chamber 22, from which one or more transverse ports 23 lead to the exterior of the valve-box. The mouth of the port 21 is provided with a valve-seat 24.

A ball-valve-25 is located inthe chamber 15 and normally rests on its seat 24, closing thel exhaust-port 21. l

A rod 26 leads from thegcore 3 of the electromagnet up through the valve-box 9 into engagement `with the bottom of the ballva ve 25. v

The valve-box 1 is provided with a valve- .chamber 27 the upper end of which is closed by a removable top cap 28, havlng a screwthreaded engagement With the Wall of the said chamber. A ressure -port 29 leads through this cap an is fitted to be connected tothe receiver 48 of the compound air-compressor 44 through a piipe 49. The mouth of this port 29 is provide with a valve-seat 30..

A pressure-port 3 1 leads through the valvebox to the chamber 27, ,which to be connected t0 the back of t e discharge- -valve 50 of thel high -pressure cylinder 'of the'compound air-compressor 44 through a pipe 51.

port is fitted IOO A ring 32 is seated in the bottom of the chamber 27, the bore of which ring forms an exhaust-port 33, which leads to a central chamber 34, from which one or more transorts 35 lead to the exterior of the valveox. The mouth of this port 33 is provided with a valve-seat 36.

The ball-valve is' denoted by 37 and normally-.rests on its seat 36. vA rod 38 rests on the core 4 of the electromagnet 'and extends upwardly through the valve-box into engagement with the bottom 'of the ball-valve 37.

The operation of the unloader is as follows: When the electromagnet is denergized, the valves 25 and 3'7 rest upon their exhaust-port seats 24 36, thus opening communicationfrom the pressure-ports of the intercooler and receiver to the pressure-ports of the high and low pressure discharge-valves.

When it is desired to remove the pressure from the backs of the dischar e-valves for unloading the compressor, the e ectromagnet is energized. This will raise the cores 3 and 4 and the rods 26 38, thereby raising the valves 25 37 away from their exhaust-port lseats into position t-o close the. seats lof the pressure-ports leading to the intercooler and receiver. This will open communication from the pressure-ports leadin to thel high and low pressure dischar va ves to the atmosphere through the e aust-ports20 and 3 3.

It is desirable that the upwardmovements of the rods 26 and 38 be retarded to a certain extent when the electromagnet 2 is energized, so as to prevent a too rapid shifting of the valves 25 and 37. This ob'ect is accomplished by making the valveoxes 9 and 10 of some magnetic material--such, for instance, as magnetic iron-so that when the electroma t 2 is energizedf 'a certain amount o magnetism is imparted to the said valve-boxes 9 and 10. The attraction of the rods 26 and 38 to the valve-boxes 9 and A10 will be sucient to retard tlupward movements of the rods through the bores of the said valve-boxes. retarding'eifect on the rods will reduce the noise incident lto the valves 25 and 37 striking their seats 18 and 30.

To prevent the accumulation of oil, I provide longitudinal ducts 3.9 40, which extend through the cores 3 and 4 and coact with ducts 41 42 in the bottom caps 7 and 8.

The interior of the valve-chambers are readily accessible by removing the top caps 16and 28. permits the ready renewal of thelbail-l-valves and also of the rings. It

- also vpermits the ready substitution of new to caps when necessal.` y

`n F 3 I have s own in diagram an electrica system suitable for use in operating the eleotromagnet 2 of the unloader. This system 'comprises in aa general wayamot-or 52,

opening and closing the having a shunt-winding 53'anda series winding 54, a starting resistance 55, a magnetic clutch 56; an automatic switch 57, its magnetic blow-out 58, a magnetic-controlled convalves therefor and an unloader provided,

with a lplurality of valve-chambers, each valve-chamber having a pressuresup ly port, an exhaust-port and a dischar e-va ve port in communication with the bac of one of the discharge-valves, a valve for alter.- nately opening and closing communication from the pressure-supply port and exhaustport to the discharge-valve port and electrically-controlled means Afor operating the valves.

2. A compound air-compressor, dischargevalves therefor and an unloader provided with a pluraiity of valve-chambers, each chamber having a pressure-supply port, an exhaustport and a discharge-valve port' in communication with the back of one of the discharge-valves, a ball-valve for alternately pressure supply and exhaust ports to the discharge-valve port and .means for operating the ball-valves.

3. A compound air-compressor, dischar evalves therefor and an unloadcr provi ed with a plurality of valve-chambers, each lclx'amber having a ressure-su pl ort, an exhaust-part and apdisoh'a p y P communication with the back of one of the Vdischarge-valves, a ball-valve for alternately op Vning and closing the pressure supply and exhaust ports to the discharge-valve' port and electricaliy-controiled me nsfor operating the ball-valves. Y

4. A compound air-compressor, discha evalves therefor and an unloader provi with a plurality of valve-chambers, each chamber having la pressure-supply port, an exhaust-port and la discharge-valve port in communication with the back of one of the ydischarge-valves, a valve arranged to alternately open and close the pressure sup ly and exhaust .ports to the ydischarge-valve port, and a single electromagnet for simultaneousy operatin `the valves.

valves therefor and an unloader comprisinga pluraflity 'of valve-boxes, each valve-'box be.

ing provided with la chamber having a pressure-supply port, an exhaust-port and a discharge-valve port in communication with the back of one ofthe discha e-valves, a valve for lalternately opening closing the pres- IOC rge-valve port in I 2 O compo/un4 air-compressor, dischargesure supply and exhaust ports to the discharge-valve port and a single electromagnet for simultaneously operating the valves.

6. A compound air-compressor, low and high pressure discharge-valves therefor and an unloader provided With a plurality of chambers, one chamber having a pressuresupply port, an exhaust-port and a low-pressure discharge-valve port in communication With the back of the low-pressure valve, a valve for alternately opening and closing the pressure supply and exhaust ports to the W- pressure discharge-valve port and another chamber having a pressure-supply port, an exhaust-port and a high-pressure dischargevalve port in communication with the back of the high-pressure discharge-valve, a valve for alternately opening and closing the pressure Supply and exhaust ports to the highpressure discharge-valve port, and an electromagnet for operating the valves.

7. Acompound air-compressor, low and high pressure discharge-valves therefor, an intercooler, a receiver and an unloader provided With a plurality of valve-chambers, ronge chamber having a pressure-supply port communicating with the intercooler, an exhaust-port and a discharge-valve port in communication with the back of the lowpressure discharge-valve, a valve for alternately opening andb closing the intercooler pressure supply and exhaust ports to the lowpressure discharge-valve port, another chamber having a pressure-supply port communicating with the receiver, an exhaust-port and a discharge-valve port in communication With the back of the high-pressure dischargevalve, a -valve for alternately opening and closing the receiver ressure supply and exhaust ports to the gh-pressure dischargevalve port, and an electromagnet for operating the valves.

8; A compound air-compressor, lov;r and high pressure discharge-valves therefor, an

intercooler, a receiver and an unloader provided- With a plurality of chambers, one chamber havin a pressure-supply port communicating Wit the intercooler, an exhaustport and a low-pressure dischar e-valve port in communication with the bac of the lowpressure discharge-valve, a valve for alternately opening and closing the intercooler pressure supply and exhaust ports to the lowpressure discharge-valve port, another chamber having a pressure-supply port communicating with the receiver, an exhaust-port and a high-pressurel discharge-valve port in communication With the back of the high-pressure discharge-valve, a valve for alternately opening and closing the receiver pressure supply and exhaust ports to the high-pressure discharge-valve port; and an electromagnet for operating the valves.

9. A compound air-compressor, dischargevalves therefor and an unloader provided with a plurality of valve-chambers having pressure-supply ports, exhaust-ports and discharge-ports in communication with the backs of the discharge-valves, valves for alternately opening and closing the pressure-supply ports and exhaust-ports to the dischargevalve ports, a single electromagnet of the solenoid type having two cores and rods interposed between the cores and the valves thereby bringing the valves under the control of the operation of the electromagnet.

In testimony that I claim the foregoing as my invention I have signed my name, in resence of two Witnesses, this 14th day o November, 1904.

FREDERICK ,VAN DUZER LONGACRE.

Witnesses:

FREDK. HAYNEs, HENRY THIEME. 

